In the open letter to his constituents, Mr O’Mara apologised for any offence his online comments from 2002 and 2004 had caused, but added: “I didn’t commit any crimes, yet I have been made unfairly to feel like a criminal.

“Nobody should be made to feel ashamed for mistakes they make when they are young.”

‘Wish him well’

Mr O’Mara claimed “the Labour Party no longer shares my commitment to the true definition of equality and compassion”.

“I would be lying to those of you whom I represent, and those close to me like my parents and sister respectively, if I continued under the pretence that I feel there is a place of acceptance and empathy for me as a working class, underprivileged disabled man within the Labour Party,” he said.

“I have experienced little to make me feel welcome, understood and accepted during this last year.”

A Labour Party spokesperson said: “We’re disappointed Jared has decided to resign from Labour after we won the Sheffield Hallam seat from Nick Clegg and the Lib Dems last year.